In real life, scenes can oftentimes include a very high dynamic range, where the “dynamic range” of a scene can be defined as the luminance ratio between the brightest and the darkest objects in the scene. For example, a scene including a tree on a bright, sunny may have both bright areas where the sunlight is illuminating objects and very dark areas that are within the shade of the tree, thus resulting in a wide dynamic range for that scene. Nowadays, various imaging system have been developed to effectively capture images of such high dynamic range (“HDR”) scenes. As an example, one method of HDR imaging can capture several low dynamic range images, where each low dynamic range image is taken under a different exposure time. For example, one low dynamic range image can have a long exposure time to suitably capture the dark areas of the scene, another low dynamic range image can have a short exposure time to suitably capture the bright areas of the scene, and so forth. The several low dynamic range images may then be combined to form a single, HDR image that can clearly portray image features ranging from dark shadows to bright lights.
However, even though imaging systems have been developed to capture HDR images having a wide luminance range, the portrayal of such HDR images can be limited by the display device used to display the HDR image. For example, nowadays a typical liquid crystal display (“LCD”) monitor can have a contrast ratio of, for example, 1,000:1, where the “contrast ratio” of a display device can define the ratio of the luminance of the brightest color to the darkest color that the monitor can produce. However, a typical HDR image can have a dynamic range of, for example, 250,000:1. In other words, it may not be uncommon for an HDR image to have a greater dynamic range than a display device attempting to display that HDR image. Accordingly, in order to reproduce the HDR image on the relatively low dynamic range display device, the luminance range of the HDR image can be compressed to within the available luminance range of the display device. This technique for compressing the luminance range of the HDR image to the range of the display device can be referred to as “tone mapping.”